The Yosemite fire grew to more than 200 square miles Sunday, threatening two groves of giant sequoias as well as the Hetch Hetchy Reservoir supplying water and power to San Francisco, consuming some two dozen structures and threatening 4,500 more.

What’s called the Rim Fire is just 7 percent contained. And while its spread slowed somewhat Sunday, it continued to grow.

"This fire has continued to pose every challenge that there can be on a fire: inaccessible terrain, strong winds, dry conditions,” said Daniel Berlant, spokesman for the California Department of Forestry and Fire Protection. “It's a very difficult firefight.”

High winds are making that firefight even more challenging as ground-level blazes whip up to treetops, creating what are called crown fires.

"A crown fire is much more difficult to fight," said Mr. Berlant. "Our firefighters are on the ground having to spray up."

As the fire threat moved, some evacuation orders were lifted. But the San Jose Mercury News reports that residents were advised to clear out of several other settlements, including Tuolumne City and Ponderosa Hills, where homes are scattered throughout the woods.

The bulk of the fire is to the west of Yosemite National Park, and as of Sunday most of the park facilities in Yosemite Valley remained open to visitors, although officials closed some campgrounds and wilderness trails at higher elevations.

“Most of Yosemite National Park is not affected by the fire and is relatively smoke-free,” according to the park’s website. “The northern part of the park, including some areas along the Tioga Road, has some smoke. Conditions may change if winds shift.”